Rheumatoid arthritis is a chronic autoimmune disease that affects about 1 percent of the adult population in the United States. It is marked by severe inflammation of the joints.
The cause is unknown, but likely involves genetic and environmental factors. If left uncontrolled, the condition can lead to destruction of the joints and significant disability within 10 to 20 years from onset.
The typical presentation consists of a gradual onset of arthritis in the fingers, hands, wrists, and toes. Affected individuals experience of pain, morning stiffness, and joint swelling. In addition, symptoms can occur outside the joints, including eye disease, heart disease, vascular disease, and anemia.
Prevalence varies widely among ethnic and regional groups. For example, less than 1 percent of rural Africans are affected, compared with 5 percent of Pima Indians. Other risk factors include:
- Age: The typical age of onset is 30 to 55 years, although the disease may occur at any age.
- Gender: Rheumatoid arthritis is two to three times more common in women than in men.
- Genetics: Certain genes increase the risk of disease.
Rheumatoid Arthritis: Diagnosis and Treatment
The diagnosis of rheumatoid arthritis is largely based on the characteristic symptoms and physical examination. No single laboratory or imaging study is definitive.
The American Rheumatism Association has established seven clinical signs, four of which must be present for diagnosis:
- Morning stiffness in or around joints, lasting at least one hour
- Swelling and pain of three or more joint areas lasting at least six weeks
- Swelling of the finger, hand, or wrist joints lasting at least six weeks
- Symmetric swelling (arthritis) lasting at least six weeks
- Rheumatoid nodules
- A positive blood test for rheumatoid factor, which is found in about 85 percent of patients
- X-rays that show typical findings of rheumatoid arthritis, including erosions of bone and loss of bone in the joint areas
Treatment of rheumatoid arthritis generally includes physical therapy, dietary intervention (see Nutritional Considerations), anti-inflammatory medication, and disease-modifying agents:
- Weight loss should be encouraged for overweight patients to decrease stress on the weight-bearing joints. Adequate rest and smoking cessation are also beneficial. Surgery is reserved for severe, debilitating disease.
- Physical therapy: Regular low-impact exercise, including aerobic exercises, strength training, and range-of-motion exercises, are important for preserving joint function. Heat therapy, relaxation techniques, and passive and active joint exercises are also helpful.
- Anti-inflammatory medications are first-line treatments. Patients who do not respond to nonsteroidal anti-inflammatory medications (e.g., ibuprofen) may find relief with steroids (e.g., prednisone). Steroids are more effective for pain relief and suppression of inflammation; however, they should be used carefully, as they can lead to bone loss, among other complications. When steroids are used, vitamin D and calcium supplementation should be instituted.
- Disease-modifying antirheumatic drugs (DMARDs) are an important treatment that may prevent joint damage, preserve joint integrity and function, reduce health costs, and maintain normal quality of life. These drugs include hydroxychloroquine, sulfasalazine, methotrexate, leflunomide, gold salts, D-penicillamine, azathioprine, and cyclosporine. However, many DMARDs have potentially serious side effects and require close monitoring.
- Newer agents that have proven beneficial for rheumatoid arthritis include anti-tumor necrosis factor α (TNF-α) agents (e.g., etanercept, infliximab, and adalimumab), and interleukin-1 receptor antagonists (e.g., anakinra). Other biological agents that target the immune system are expected to be approved in the near future.
Rheumatoid Arthritis: Nutritional Considerations
The following factors are under investigation for their role in reducing the risk of rheumatoid arthritis or for improving its course:
- Vegetarian diets: Evidence indicates that patients who follow vegan or vegetarian diets may experience significant improvement in rheumatoid arthritis symptoms. Conversely, higher intakes of meat and cholesterol are associated with an increased risk of developing this disease.
- Eliminating diet triggers: Studies have shown that eliminating certain foods brings symptomatic improvement for some people. The reason, apparently, is that certain foods trigger inflammation. Clinical tests have shown that consumption of allergenic foods increases inflammatory chemicals (cytokines) that may contribute to arthritis.
To identify trigger foods, an elimination diet can easily be instituted as follows:
Start with a simple baseline diet, excluding foods that are more common triggers (such as dairy products, corn, meats, wheat, oats and rye, eggs, citrus fruits, potatoes, tomatoes, nuts, and coffee), and including only those foods not implicated in arthritis, listed below:
- Brown rice.
- Cooked or dried fruits (cherries, cranberries, pears, prunes).
- Cooked green, yellow, and orange vegetables (artichokes, asparagus, broccoli, chard, collards, lettuce, spinach, string beans, squash, sweet potatoes, tapioca, and taro).
- Plain or carbonated water.
- Condiments (modest amounts of salt, maple syrup, vanilla extract).
After approximately four weeks on this diet, if symptoms have improved or disappeared, patients may introduce previously eliminated foods one at a time, every two days. As they do so, patients should keep a food diary and add these foods in generous amounts to observe which cause arthritic symptoms. Foods listed above as common triggers should be added last. A newly added food associated with increased joint pain should be removed from the diet for one to two weeks, and reintroduced to see if the same reaction occurs. If no symptoms are experienced, that food can be kept in the diet. It is suggested that meats and dairy products not be returned to the diet, regardless of their effect on joint symptoms, due to their contribution to heart disease and other conditions.
- Fruits and vegetables: Studies have shown that a higher intake of certain carotenoids found in fruits and vegetables may protect against developing RA.
The European Prospective Investigation of Cancer (EPIC) study of more than 25,000 individuals found that those consuming the highest amounts of carotenoids had half the risk for developing inflammatory arthritis, compared with those consuming the least amount. Lower serum levels of vitamin E and selenium were also found to predict the development of rheumatoid arthritis.
- Caution regarding fats and oils: A diet low in arachidonic acid, an omega-6 fatty acid found in animal products, was found to decrease inflammation in arthritis patients. Further, supplementing with gamma-linolenic acid (GLA) and omega-3 fatty acids was found to be an effective strategy for reducing symptoms. These fatty acids appear to work by blocking production of inflammatory chemicals. Sources of GLA include evening primrose, borage, blackcurrent, and hemp oils. Flax oil is rich in omega-3 fatty acids.
- Folic acid supplementation: Folic acid supplementation is important for patients who are treated with methotrexate.